CPC464: Is it possible to add 64k memory internally?

[mr_lou]

My CPC464 currently has additional 64k memory externally. A big bulk of a box.

Is it possible to add these additional 64k internally, so I can have 128k total without that bulky external box?

[TotO]

Buy a 6128 and you will not have to put the external floppy drive inside too...

[mr_lou]

Buy a 6128 and you will not have to put the external floppy drive inside too...

I have a CPC6128. And a modded CPC plus too.

I was just thinking, in the near future, maybe a DDI-1 + HxC could also fit inside a CPC464. 

Just a thought.

But just having the additional 64k fitted internally would probably mean I'd use my CPC464 more.
Currently it has gotten a somewhat low status, because the RAM and DDI-I modules doesn't give the best connection, causing it to sometimes freeze.

[TotO]

OK. In this case, difficult to reach w/o serious hack.
May be better to use it "as a 464" only.

[mr_lou]

Adding an additional 64k ram internally requires a serious hack?
(Forget about the DDI-1 and HxC).

[steve]

I have an idea that somebody once replaced the 64k chips with 256k chips, but that does not tell you anything about whether it is possible or how they may have performed the bankswitching.

[Joseman]

Hi

Of course it's possible, the 6128 is a 464 expanded isn't it?

Surely it needs to cutdown a lot of tracks, "insert" in the middle the second bank, the bank switching chip, and possibly retrack this chip, i recall it shares the same I/O addresses of another chip, perhaps some condensers...

Hard work without doubt

[TotO]

First, it will be interesting to see your expansion board... 
Then, the more simple way will be to make a 50 pin Edge connector to ribbon cable, which each line soldered on the "centronics internal pins".
But, it's a quick and dirty hack. I dislike the idea.

I have an idea that somebody once replaced the 64k chips with 256k chips, but that does not tell you anything about whether it is possible or how they may have performed the bankswitching.

I already though about that in the past, as the CRTC get free address lines to support that.
In this case, all the RAM will see seen by the GA and can used for the display.
But those extra lines need a bank switching system too... Not sure that was possible to make something "standard" and usable.

[Bryce]

Yes, much the same as how I installed the MegaFlash internally on your 464+. Make an internal expansion port and connect it there.

Bryce.

[TFM]

Enjoy the soldering!

[Bryce]

It's not that difficult, it just takes quite a bit of time. You can see pictures of the internal expansion connector I did for the 464+ here: 464+ Mod

Bryce.

[TFM]

Of course, and it must not be done all at once.


NO!!! DON'T DRINK ALL THAT COFFEE BEFORE SODERING!!!